Strand treatment method and apparatus



Mzsu'ch'l7, 1970 I R. K. SYTNLEY rAL 3,500,518

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ld@ ff O O AZZ. l7 J X /7/ 3 Min/raf! RoeRT KysrANLEY @y "/(IV//V United States Patent 3,500,518 STRAND TREATMENT METHOD AND APPARATUS Robert K. Stanley, Media, and Malcolm F. Irwin, Philadelphia, Pa., assignors to Techniservice Corporation, North Kennett Square, Pa., a corporation of Pennsylvama Continuation-impart of application Ser. No. 567,245, July 22, 1966. This application Dec. 5, 1967, Ser. No. 688,119 The portion of the term of the patent subsequent to June 4, 1985, has been disclaimed Int. Cl. D02g 1/12 U.S. Cl. 28-1.6 10 Claims ABSTRACT F THE DISCLOSURE Textile strands are compressively crimped as in a stuffer crimper, at constant withdrawal or windup rate. The degree of crimp is controlled by superimposing added control tension without need for Varying the withdrawal or windup rate, although that rate may be adjusted to different constant values for a like purpose.

This application is a continuation-impart of our c0- pending application Ser. No. 567,245, now U.S. Pat. 3,386,142, filed July 22, 1966 which was a continuationin-part of our prior copending application Ser. N0. 401,160 now U.S. Patent 3,279,025.

Itis conventional to crimp a textile strand compressively by feeding it by and between a pair of nip rolls into the entrance of a temporarily confining region, the exit of which is closed wholly or partially by suitable means so that the strand accumulates therein under pressure and forces the entering strand to 'buckle into a modified Zigzag or sawtooth crimped configuration. The construction is such that the strand accumulation eventually moves the closure means sufficiently to escape from the confinement, whereupon the crimped strand may be wound up. Alternatively, the strand may be Withdrawn lengthwise from the accumulation and be slid past the closure means, but that tends to alter the crimp non-uniformly or to remove it and is, therefore, undesirable. Depending upon structure and dependability of operation, the various types of closure means, and even the individual members of a single type, vary widely from one another, as does their effect upon the strand -being crimped.

Conventional windup means and methods involve synchronization of strand windup rate and infeed rate. Alternatively, it is known to control the windup or the infeed rate (or both) in response to a sensing of the accumulation of crimped strand in either the confining region or an extension thereof or other holdup location. Usually the object is to prevent both overaccumulation of crimped strand, which might result in overflow and entanglement or breakage during windup, and underaccumulation thereof, which might withdraw uncrimped as well as crimped strand, resulting in serious non-uniformity of crimping treatment.

A primary object of the present invention is enhanced uniformity in compressive crimping of a textile strand.

Another object is simplification of strand windup in Studer-crimping apparatus and procedure.

A further object is improved control of the degree or extent of stuffer-crimp in crimped textile strands.

Other objects of this invention, together with means and methods for attaining the various objects, will be apparent from the following description and the accompanying diagrams.

FIG. 1 is a schematic representation of the processing of a textile strand according to the present invention;

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FIG. 2 is a front elevation, partly cut away, of apparatus of this invention in further detail, with strand shown passing therethrough;

FIG. 3 is a side elevation of the apparatus and strand of FIG. 2; and i FIG. 4 is a plan of the apparatus of FIGS. 2 and 3.

In general, the objects of the present invention are accomplished, in compressive crimping of a textile strand wherein the strand is fed continuously at an essentially constant rate into a laterally confining region to accumulate temporarily therein and the strand accumulation therein is forced toward the exit therefrom by additional strand fed thereagainst at the entrance to the region, the strand accumulaiton being largely or preferably entirely unconfined ahead thereof and at the exit from the region, by withdrawing the strand therefrom at a somewhat lower constant rate, by applying Winding tension thereto, ordinarily minimal in amount, and superimposing additional tension, which can be adjusted within rather wide limits, on the strand between the locus of withdrawal thereof from the strand accumulation and the windup location.

The practicability of using added tension to control degree or extent of crimp at constant windup and constant feed rate is astonishing because it would be expected that unless either the feed or windup rate were varied in strict accordance with the amount of crimped strand accumulation in the confining region, or unless the respective rates were set at a particular fixed ratio to one another, the strand accumulation would either overflow or disappear entirely. It will be apparent that adjustment of the tension from one value to another is considerably simpler and more efficient than adjustment of either infeed or windup rate, and such control facility is a principal benefit of this discovery.

FIG. 1 shows, schematically, strand 10 unwinding from conical package 11 to pass through guide 12 and successive pairs of rolls 13, 13' and 15, 15', with heater 14 for the strand intervening between the respective pairs of rolls. Pair of nip rolls 17, 17 for feeding the strand, normally at a fixed or constant rate, into stuffing chamber 18, follow after strand-traversing means 16. `Crimped strand 10 visible leaving the exit of the chamber is withdrawn therefrom and through tensioning means 19 and then denoted as 10l is wound onto cylindrical package 20 by grooved traversing drive roll 21. The stuffing chamber, feed rolls, and related stutter-crimping components are shown in greater detail, together with components of the tensioning means in subsequent views.

FIGS. 2, 3 and 4 show the indicated components and associated elements of the same apparatus in front and side elevation and plan, respectively. Part of chamber 18 is cut away in FIG. 2 to reveal crimped strand 10' and accumulation thereof in bore 28 of the chamber, which is shown in the shape of a square cylinder. Strand 10 after passing between nip rolls 15, 15' passes through strand-traversing means 16 and into the nip of feed rolls 17, 17. The latter rolls feed or stuff the strand into the entrance to the bore of the chamber, the front and rear walls of the chamber overlapping the front and rear faces of the rolls as far as the nip so as to ensure that all the strand enters the chamber. As the strand accumulates in the chamber, the entering strand meets with resistance provided by the previously accumulated strand and buckles back and forth upon itself into a modified sawtooth or zigzag configuration or crimp. As more strand is fed continuously into the chamber the compact strand accumulation is formed along through the bore toward the exit therefrom.

Chamber 18, into which the strand is stuffed and in which it assumes crimped configuration, is supported on the front wall of frame 22, which has an inverted U-shape in side elevation. Shafts 27, 27 for respective feed rolls 17, 17 are journaled in the front and rear walls of the frame and have intermeshing gears 37, 37' thereon behind the rear wall of the frame. Shaft 27 also has pulley 29 thereon. Motor 31 on the horizontal upper surface of the frame has shaft 32 on which is pulley 33. Belt 34 interconnects pulleys 33 and 29 to transmit rotational force to the gears, shafts, and the feed rolls themselves. The direction of rotation is such as to feed or stuff the strand by and`between the counter-rotating feed rolls into the entrance of the chamber. As already indicated, the infeed rate is normally constant, although it may be adjustable to different rates to accommodate different strands or changes in operating conditions.

The exit end of the chamber bore, located at the same level as the entrance in the embodiment shown in FIG. l and at a level vertically above the level of the entrance in the embodiment (which may be otherwise the same) shown in FIGS. 2, 3 and 4, is shown unobstructed, as is the rest of the bore. Crimped strand denoted as is withdrawn at a constant or xed rate, which may be adjustable if desired, from strand accumulation 100 inside and is passed through tensioning means 19, discussed in detail below. Thereafter the strand, then denoted as 10, is wound up onto bobbin or like package 20. The package is rotated by contact with the surface of rotating drive roll 21, and the winding tension so imposed on the strand (i.e., irrespective ofthat imposed by tensioning means 19) is ordinarily minimal, as on the order of a few hundredths to about a. tenth gram per denier. The drive roll is grooved helically from end to end, the groove reversing direction at each end, and thereby is adapted to traverse the strand passing over it and through the groove on its way to the package. The adjustable constant-rate drive means for the selftraversing drive roll is Conventional in design and, therefore, not shown. The same is true of drive means for the other rolls (some of which may not be driven at all), but the drive means for the feed rolls of the stutfer-crimper is shown in some detail to aid understanding thereof.

Tensioning means 19 comprises several rolls rotatably mounted on a supporting framework and means for retarding rotation of the rolls so as to superimpose tension on stand 10' passing thereover. Framework 40 has at one side vertical flange 50 extending downward alongside stuliing chamber 18 and adjacent lateral extension 18a thereof to frame 22 to which it is atlixed. Supported on the framework, first roll 41 on axle 41a and third roll 43 on axle 43a are both contiguous with minor cylindrical portion 42 of second roll 42, which is mounted on axle 42a parallel to the other two axles. The lirst and third rolls do not touch one another. Strand 10;' passes about slightly less than half of each of the irst and third rolls and about three-fourths of the minor portion of the second or intermediate roll, passing between the nip formed by each of the first and third rolls with the latter, after which the strand is denoted as 10". Belt or strap 52 extends about a quadrant of the major portion of roll 12 from a fixed location on ange 50 at one end to stop 53 at the other end, upon which are supported weights 54, thereby biasing the belt or strap into frictional contact with the roll surface.

Strand 10 is pulled, as by the windup means shown in FIG. 1 (or by draw rolls, etc.), in essentially nonslipping contact with rst roll 41, minor portion 42' of the second roll, and third roll 43, thereby rotating them in the directions indicated by the arrows. The major portion of roll 42 rotates in slipping frictional Contact with belt or strap 52, which counters the positive rotation and thereby tensions the strand. The tension can be increased by adding weights, and reduced by subtracting weights, caried by the belt or strap. Suitable tensions for nylon strands of about 2000 total denier and 140 filaments are on the order of tenths of a gram per denier, depending upon the desired degree of crimp, half a gram per denier often being a satisfactory value. The resulting tension in the strand is essentially constant at a maximum value determined by the frictional contact just described, which tends to smooth out preexisting tension irregularities in the strand. As the control is passive, rather than active, it cannot superimpose additional tension variations upon the strand. Adjustment is simplicity itself, and maintenance is practically nil.

When the apparatus of this invention is being started up, it is desirable to insert a rod or the like in the open end of chamber 18 to compress the irst bit of strand being fed therein until a Wad of crimped strand has accumulated, after which the accumulated strand may be allowed to be forced further in the chamber from the entering end, accumulating additional strand in crimped conliguration behind it. Contrary to prior practice, no added means is necessary to apply crimping back pressure to the strand during operation of the apparatus of this invention, although some could be used at or upstream from the furthermost downstream location of the compact accumulation of crimped strand, if desired, but predictably with less beneficial effect. Despite the lack of physical obstruction of the chamber the apparatus may be operated with the chamber in any desired orientation: e.g., horizontal as in FIG. 1, upright as in succeeding views, or at any intermediate angle, and even inverted (not shown).

As described, the strand is wound up from the accumulation in the chamber at a constant rate and under tension suicient to keep the furthest extent of the strand accumulation at some distance from the end of the chamber, usually within the range of from about two-thirds to about nine-tenths of the infeed rate. No means or method for synchronizing windup and feed rates is required, as the crimped strand will accumulate to a substantially constant level in the chamber, rising only slightly thereabove and falling only slightly therebelow, that level being determinable by setting the overall tension and, of course, by the physical characteristics of the strand, as well as the temperature, wall friction, etc. Adjustment of the superimposed tension effects control of the degree or extent of crimp in the strand, the tension and the crimp varying in the same sense with respect to one another. Thus, a high tension produces an increased degree of crimp, together with a highlevel of strand in the chamber, as compared with a low levelV of strand and decreased crimp at a lower tension. Degree of crimp may be determined by any conventional method, and high crimp may be apparent in part as increased crimp frequency, reduced crimp leg length, reduced angle between adjacent legs, increased crimp retention under tension, or any combination of these with one another, or possibly other crimp characteristics.

Strand crimped according to the present invention is free of undesirable irregularities attributable to uneven application of back-pressure by devices such as have been used in conventional stufer-crimping apparatus or to uneven application of heat to the strand therein. Heater 14 heats the strand to desirable crimping temperature (e.g., l50-350 F.), and the stuing chamber may be heated, as by a heating jacket or by resistance coils in the chamber wall (neither shown) to preclude cooling or excessive cooling of the strand in the chamber, although it normally will be at an appreciably lower temperature at the exit (e.g., about F.) than at the entrance of the chamber. Any suitable means may be used to preheat the strand, such as hot rolls, a bar type of heater, etc. instead of the illustrated heated chamber. The actual heater temperature will depend upon the degree of lubrication (if any) and rate of travel of the strand (1000- 2000 yards or meters per minute is preferred) as well as upon the strand composition and denier, the chamber composition, and the method of heating (conduction, convection, radiation, etc.). The stufling chamber and other apparatus elements may be made of steel or other durable material. If desired, the inside wall of the charnber may be coated (c g., with tetrauoroethylene) to reduce the coefcient of friction, in which event the chamber should be lengthened accordingly. A chamber length of about a yard or meter (inner width about 1A inch or a centimeter for use with strands of about l0 to 100 denier) has proved suitable for nylon and other commonly available textile strand materials.

Although a preferred embodiment of this invention has been illustrated and described, by way of example, modifications may be made therein while retaining all or some of the advantages and benefits of the invention. Minor restriction or impedance of the strand in its path through the temporarily confining region, preferably in the vicinity of the feed rolls rather than further downstream, may be employed if desired. Parts may be added, combined, rearranged, or subdivided and equivalents be substituted without departing from the invention.

What is claimed is:

1. In stutfer-crimping of a textile strand wherein the strand is fed continuously at an essentially constant rate into a laterally confining region having an entrance and an exit to accumulate temporarily therein and the strand accumulation therein is forced toward the exit by additional strand fed thereagainst at the entrance to the region, whereupon a crimped conguration is imparted to the strand, the improvement comprising controlling the degree of crimping by withdrawing crimped strand from the accumulation thereof and out of the exit by application of winding tension thereto and superimposing an essentially unvarying, though Variable, additional tension on the strand between the locus of withdrawal thereof from the strand accumulation and the windup location.

2. The process improvement of claim 1 wherein the withdrawal of the strand is at a preadjusted, essentially constant rate, which is less than the feed rate.

3. The process improvement of claim 1 wherein the degree of crimp varies in accordance with the superimposed tension, and including the step of preadjusting the superimposed tension to a constant value at which a preselected degree of crimp is obtained in the strand.

4. The process improvement of claim 1 wherein the strand is preheated before being fed into the laterally confining region to accumulate temporarily therein and is maintained at elevated temperature without absorbing further heat while in the confining region.

5. In stutter-crimping of a textile strand, the improvement comprising feeding the strand continuously into a laterally confining region to accumulate temporarily therein, utilizing at least principally friction of lateral connement of the strand accumulation therein to apply crimping back-pressure to the strand being fed into the region,

and removing strand therefrom by winding it up from the leading edge of the strand accumulation, controlling the degree of crimp imparted to the strand by adjusting to a desired constant value the tension on the strand being wound up, the windup rate being essentially constant.

6. The process improvement of claim 5 wherein essentially only the friction of lateral confinement of the strand is utilized to apply crimping back-pressure to the strand being fed into the confining region, the strand accumulation being unconned ahead thereof, and wherein the strand is fed into the confining region at a constant rate within the range of about one-tenth to about one-half greater than the windup rate.

7. The process improvement of claim 5 wherein the strand is fed at a rate of at least a thousand yards per minute into the laterally confining region and the strand is wound up therefrom at a constant rate on the order of about one sixth less than the feed rate, which is also constant.

8. In apparatus for stuffer-crimping a textile strand, a confining chamber having a bore therethrough open at both ends, means adapted to feed strand at a constant rate into the chamber bore to accumulate temporarily in compact form and be crimped therein, the chamber bore and exit being essentially free of strand-impeding means operative upon the compact strand accumulation, means for withdrawing crimped strand from the compact accumulation thereof at a constant rate that is lower than the feed rate, and including adjustable strand-tensioning means for the crimped strand in advance of the withdrawing means.

9. The apparatus of claim 8, wherein the tensioning means includes at least one roll over which the strand passes in essentially non-slipping contact therewith and means operatively connected to retard the roll rotation and thereby tension the strand.

10. The apparatus of claim 9` wherein the retarding means includes a plurality of elements in sliding fricitonal contact with one another.

References Cited UNITED STATES PATENTS 3,311,961 4/1967 Iwnicki et al 28-72 3,341,913 9/1967 Jenkins et al 28-72 3,386,142 6/1968 Stanley et al 28-1 3,394,439 7/ 1968 McIntyre 28-1 LOUIS K. RIMRODT, Primary Examiner U.S. Cl. X.R. 28-72. 14 

